The removal of solids in severely depleted wells remains as one of the most challenging intervention operations in the oil and gas industry.
A number of procedures have been employed to date for the cleanout of wellbores. Such procedures include the use of water/gel slugs followed by significant volumes of nitrogen to impart temporary diversion to control fluid loss; the use of foam or linear gels as diversion agents; the use of solid diversion agents, such as benzoic acid flakes and grade calcium carbonate pills; and the use of concentric coiled tubing sand vacuuming. These methods, however, present logistical challenges as they are time consuming and often largely ineffective in the treatment of under hydrostatic pressure wells. Alternatives for the cleanout of wellbores have been sought.
It should be understood that the above-described discussion is provided for illustrative purposes only and is not intended to limit the scope or subject matter of the appended claims or those of any related patent application or patent. Thus, none of the appended claims or claims of any related application or patent should be limited by the above discussion or construed to address, include or exclude each or any of the above-cited features or disadvantages merely because of the mention thereof herein.
Accordingly, there exists a need for alternative methods for improving the efficiency of cleaning out depleted wells having one or more of the attributes or capabilities described or shown in, or as may be apparent from, the other portions of this patent.